One of the ways to power a torpedo is to utilize metallic lithium mixed with sulfur hexafluoride as a fuel. This fuel is placed in a boiler and ignited, thereby generating the heat necessary to boil the working fluid and drive the propeller. The engines of the torpedoes are run for varying periods of time resulting in mixtures of spent fuel in which large amounts of lithium fluoride and lithium sulfide are present in the reaction products. After completion of a test run, the spent fuel is present in the boiler as a solid cake consisting essentially of lithium fluoride and lithium sulfide within which lithium metal is still present. Decontamination of this boiler is expensive and hazardous since lithium reacts slowly in air and violently with water, and in addition the lithium fluoride is both toxic and insoluble in most solvents.
Manufacturers and users of these torpedo boilers have to find some method to solve the decontamination problem. The boiler is an integral part of the torpedo and it would be preferable to clean the boiler intact prior to possible reuse. At present, the process used consists of attempting to break up the lithium fluoride matrix by severing the boiler and subjecting it to pulses from a water cannon. This process is hazardous in that the lithium produces flammable hydrogen gas in the presence of water and because of the aforesaid lithium fluoride toxicity. It is therefore desirable to discover a solvent-based system for dissolving the lithium fluoride matrix, thereby releasing the unreacted lithium metal and permitting recovery of lithium and its salts.